Arthttb henry gibson



A. H.- GIBSON Feb. 3, 1931.

OIL SWITCH Filed June 4. 1928 2 Sheets-Sheet l A. H. GIBSON Feb. 3, 1931.

OIL SWITCH Filed June 4. 1928 2 Sheets-Sheet 2z llllIlllIllIIl/ll A llllllllllll'l'lllllll l Il d Patented Feb. 3, 1931 UNITED STATES ARTHUR HENRY GIBSON, OF HOLDEN, ALBERTA, CANADA OIL SWITCH Application 'lled June 4, 1928.

In all switches known to me, when contact is broken an arc is formed which acts on the surrounding oil to form a gas, which results in a gas filled cavity between the contacts having an electrical conductivity which supports the arc. This conductivity is such that the arc is often maintained for a considerable period.

To overcome this unsatisfactory feature of oil switches means have been devised for uti lizing the torce generated by the creation of the gas to inject a jet of oil between the cont-act points after they have been separated. Most of such devices have been unsatisfactory because instead of an injection of cold unvaporized oil, an injection of hot or gasified oil has been secured, and instead of directing the oil across the line of the arc, it is forced in a direction parallel thereto and thus JIails to a certain extent to attain its object.

The object of this invention is to provide means whereby a jet of cold unvaporized oil is injected between the contacts of an oil switch at substantially right angles to the arc and at a definite time interval from the breaking of 2b the contact.

I attain my object by enclosing the switch contacts in an air and oil tight casing capable oi' withstanding high pressure. The casing is filled with insulating oil, and means are provided for operating the switch without disturbing the air and oil tight condition of the casing. Within the chamber is a piston adapted to be operated by the pressure generated by the arc to direct a jet of oil between 35 the contact points of the switch.

rIlhe device isA hereinafter more fully described and illustrated in the accompanying drawings in which Fig. 1 is a vertical section through the centre of a single pole oil switch;

Fig. 2 is a vertical section of the same, taken at right anales to Fig. 1 on the line 2-2;

Fig. 3 is a vertical section through the cen- 45 tre o' a double pole switch;

Fig. i is a cross section of the same on the line 4 4.; and

Fig. 5 is a cross section on a larger scale of the packing gland shown in Fig. 2.

In the drawings like numerals of reference Serial No. 282,670.

indicate corresponding parts in the different igures.

In Figs. 1 and 2, 1 is the switch chamber and 2 is the oil supply chamber which has a removable top 2a and an opening 2b therein 55 communicating with the atmosphere. A nonreturn valve 8 is located in an opening between the oil supply chamber and the switch chamber and permits oil to How from the oil supply chamber to the switch chamber. Conductors 4 and Il@ pass through insulators 5 into the switch chamber.

The switch comprises a switch arm 6 pivotally connected with the conductor 4, said switch arm being provided with a contact Ga. This Contact is adapted to engage an auxiliary Contact 7 which is connected with the conductor 4a. In the switch arm 6 is a slot 6b.

A roller 8 is adapted to run in the slot 6" and is rotatably mounted in an insulator 9 70 which is secured to the inner end of a sliding rod 10. The insulator 9 is adapted to slide on rods 13 which are arranged within the chamber parallel to the sliding rod 10. The sliding rod 10 passes through an opening 1 75 in the wall of the chamber 1 and its outer end is pivotally connected with a lever 11 whicn is fulcrumed on a link 12. This link is pivoted on any suitable stationary part. A packing gland 13 is provided to prevent leakage 80 of air and oil between the rod 10 and the wall ot' the chamber.

The slot 6b is inclined relative to the line oi movement of the roller so that when the sliding rod 10 is withdrawn the roller 8 bears 85 on the switch arm to cause it to swing outwards out of Contact with the contact 7.

A dilierential piston 15, the portion thereof having the larger diameter being indicated by 15a and the portion having the smaller 90 diameter by 15b, slides in a differential cylinder 16, the portion thereof having the larger bore being indicated by 16a and the portion having the smaller bore being indicated by 16". The cylinder opens into 95 the switch chamber 1 and a spring 17 tends to force the piston towards the opening 18 between the cylinder and the chamber 1. This opening 18 is of smaller diameter than the bores 16a and 16" of the cylinal der, and a reduced portion 15c of the piston entends therethrough. rlhe diameter of this portion 15c is slightly smaller than that of the opening 13, and the end thereof may be slightly convex. The end or" the cylinde 1 adjacent the opening may be dished. rlhis formation prevents oil from being trapped between the end of the piston and the end of the cylinder, and, by allowing oil to escape gradually, prevents the piston from striking the end of the cylinder with a sharp blow when the spring 17 forces it into Contact therewith. A small opening 19 is formed in the head of the piston 15. This provides an outlet for or air that may be trapped in the hollow end of the piston.

A port 2O opens into the large bored portion 16a of the cylinder a short distance from thefend of the stroke ,ot the piston. rl`his port communicates with a passage 2l which communicates with the oil supply chamber 2.

A small port 2O'nl communicates with the passage 21 and the cylinder 16a just below the port 20. The small port 2()L remains open after the port 2O has been closed by the piston and serves to gradually checlr the movement of the piston on its downward strolre.

Passages 22 connect the bottom of the lower end 16b of the cylinder with two nozzles 23 which are disposed at opposite sides ot the contacts 6a and 7 and are directed at right angles to the line of movement of the switch arm 6 when the switch is opened.

The operation or" the switch is as follows: The cil chamber 2 is supplied with suihcient oil to keep the switch chamber 1 and the cylinder 16 supplied with oil. Y

Vhen the switch is opened an arc is formed between switch arm contact 6"L and the contact 7. This causes a gasification et the oil and generates a high pressure in the switch chamber. Pressure is exerted on the head of the piston 15 and through the nozzles and passages 22 on the rear of the piston. Howover, since a portion of the piston 15 equal to the dilierence between the diameter oit the portion 15?L and the diameter of portion 15b is exposed on its lower side only tothe atmospheric pressure of the oil chamber 2 the piston is forced down and expels the oil rr-om the cylinder through the passageways and the nozzles 23, thus injecting a stream of cold oil into the arc at substantially right angles to the line thereof.

Various modifications of the above described construction are possible7 one of which is shown in Figs. 3, 4 and 5, which represent a modilication used for a double pole switch. Two air and oil tight switch chambers 30 are provided. Since each or" these chambers is exactly the same, only one is described. A conductor 31 passes through an insulator 32 tov a spring Contact 33. A sliding conductor 34 passes through an insulator 35 and is adapted to engage the contact 33. The sliding conductor is operated from outside the switch by an insulated cross head 36. Where the sliding conductor 24 enters the chamber from the insulator a special packing is provided as shown in Fig. 5, consisting of a ring of thin oil tanned leather 37 held in place by the ring 38. Such a packing packs perfectly on a smooth rod and the pressure on the leather ring 37 forces it into close contact with the rod.

An oil supply chamber 39 has an opening 39a to the atmosphere and has a very small passage 38 connecting it with the top of the switch chamber 30. Below the oil supply chamber and communicating with it and with the switch chamber 30 is a dierential cylinder 40 in which a ditiierential piston 41 is adapted to slide. The portion 40a ot the cylinder having the smaller bore 'opens directly in toI the oil chamber 39. Near the top of the larger portion 40b of the cylinder is a passage 42 communicating with a nozzle 43 arranged at substantially right angles to the line of movement ot the sliding conductor and just above the contact 331 The part 41CL oi' the piston having the smaller bore is adapted to slide in the portion 40a or" the cylinder and the part 41b of the piston in the portion 40b or" the cylinder. Thus when the switch is opened and an arc is formed the part 41a of the piston will be subject to atmospheric pressure only on its upper side, and the pressure generated by the arc will torce the piston up, causing the oil to be expelled from the piste-n through the passage 42 and nozzle 43.

A coil spring 44 guided by a supporting rod 45 is adapted to return the piston to the bottom lof the cylinder. rlhe lower end of the cylinder 40 adjacent the opening into the switch chamber and the lower end oi the piston may be constructed similarly to the corresponding parts in the single pole switch.

`While only two forms of the invention have been described7 l do not wish to be confined to Ythese forms or the details of construction of either of them.

What I claim is:

1. In an oil switch, a substantially air and oil tight chamber containing oil and switch contacts; means for opening the switch without disturbing the air and oil tight condition of the closed chamber; a dir"- erential cylinder containing oil; a differential piston therein exposed to the liuid pressure in the chamber and adapted to be actuated by the rise in pressure caused by the formation of an arc when the switch is broken; and means communicating with the cylinder adapted to direct a jet of oil between the contacts.

2. ln an oil switch7 a substantially air and oil tight chamber containing oil and switch contacts; means for opening the switch without disturbing the air and oil tight condition of the closed chamber; a cylinder containing oil; a piston therein exposed to the fluid pressure in the chamber and adapted to be actuated by the rise in pressure caused by the formation of an arc when the switch is broken, part of the surface of the piston remote from the opening into the oil chamber being constantly at atmospheric pressure; and means communicating with the cylinder adapted to direct a jet of oil between the contacts.

3. In an oil switch, a substantially air and oil tight chamber containing oil and switch contacts; means for openin g the switch without disturbing the air and oil tight condition of the closed chamber; a cylinder containing oil and opening into the closed chamber, the bore of the cylinder adjacent the closed chamber being greater than the bore remote therefrom; a passage communicating between the enlarged part of the cylinder and the atmosphere; and means communicating with the smaller part of the cylinder adapted to direct a jet of oil between the contacts.

4. In an oil switch, a substantially air and oil tight chamber containing oil and switch contacts; means for opening the switch without disturbing the air and oil tight condition of the closed chamber; a cylinder containing oil; a piston therein exposed to the fluid pressure in the chamber and adapted to be actuated by the rise in pressure caused by the formation of an arc when the switch is broken; a second chamber communicating if, with the atmosphere; a space behind the piston communicating with said second chamber; and means communicating with the cylinder adapted to direct a jet of oil between the contacts.

5. In an oil switch, a substantially air and oil tight chamber containing oil and switch contacts; means for opening the switch without disturbing the air and oil tight condition of the closed chamber; a cylinder con- H, taining oil; a piston therein exposed to the fluid pressure in the chamber and adapted to be actuated by the rise in pressure caused by the formation of an arc when the switch is broken; a second chamber communicating with the atmosphere, said second chamber being adapted to contain oil; a non-return valve through which oil may How from the second chamber to the first mentioned chamber; a space behind the piston communicating with said second chamber; and means communicating with the cylinder adapted to direct a jet of oil between the contacts.

6. In an oil switch, a substantially air and oil tight chamber containing oil and switch contacts; means for opening the switch without disturbing the air and oil tight condition of the closed chamber; a differential cylinder containing oil; a differential piston therein exposed to the fluid pressure in the chamber and adapted to be actuated by the rise in pressure caused by the formation of an arc when the switch is broken; means communicating with the cylinder adapted to direct a jet of oil between the contacts; and means tending to return the piston to the end of the cylinder which is open to the oil chamber.

7. In an oil switch, a substantially air and oil tight chamber containingV oil and switch contacts; means for opening the switch without disturbing the air and oil tight condition of theclosed chamber; a cylinder containing oil and o ening into the closed chamber,the bore o the cylinder adjacent the closed chamber being greater than the bore remote therefrom; a passage communicating between the enlarged part of the cylinder and the atmosphere, said passage having a port opening into the cylinder at such a position that the enlarged portion of the piston will close the port just before finishing its stroke; and means communicating with the smaller part of the cylinder adapted to direct a jet of oil between the contacts.

8. In an oil switch, a substantially air and oil tight chamber containing oil and switch contacts; means for opening the switch without disturbing the air and oil tight condition of the closed chamber; a cylinder containing oil and opening into the closed chamber, the bore of the cylinder adjacent the closed chamber being greater than the bore remote therefrom; a passage communicating between the enlarged part of the cylinder and the atmosphere, said passage having a port opening into the cylinder at such a position that the enlarged portion of the piston will close the port ust before finishing its stroke; a smaller port located nearer the end of the piston stroke, the two ports being adapted to be successively closed by the piston to gradually check the movement thereof; and means communicating with the smaller art of the cylinder adapted to direct a. jet ooil between the contacts.

9. In an oil switch, a substantially air and oil tight chamber containing oil and switch contacts; means for opening the switch without disturbing the air and oil tight condition of the closed chamber; a nozzle adapted to direct a jet of oil between the contacts when the switch is opened; oil displacing means adapted to force oil through said nozzle; and means for actuating the oil displacing means, said actuating means being eX- posed at one side to pressure generated within the chamber and at the other side, at least partly, to oil constantly at atmospheric pressure.

10. In an oil switch, a substantially air and oil tight chamber containing oil and switch contacts; an oil supply chamber open to the atmosphere; means for opening the switch without disturbing the air and oil tight condition of the closed chamber; a nozfix zle adapted to direct a jjet of oil between the contacts when the switch is opened; an oil filled Cylinder confneeted with the switch chamber and the oil supply chamber; 'and a piston operable by the rise in Huid pressure 9 caused by the formation of an are when the contacts ae separated to force a jet of oil from the cylinder through the nozzle to eX- tngush the are, and to displace e substantally equal quantity of ol from the cylinder to the oil supply chamber.

Signed at Holden, this 14th day of May,

ARTHUR HENRY GIBSON. 

